Projectile for attacking face-hardened armor.



G. DAVIS. PROJBGTILE FOR ATTAGKNG MCBy HARDENBD ARMOR.

, A PPLIUTION FILED JUNE 14, 1910.

Patented J111yv11, 1911.

, IIITE? *es rorinedvvithan;ogivalstruck.vvith-aradius of substantiallytonerdiameter lup to thefpointl ifTo" all' whom# may` concern:

-tenantfcornmanderfUnited States Navy, and" L4-vented certain` new andfA usefulV Improve- `lffiments `in Projectilesfor` Attackingv Facci` ,Hardened Armor f and- I` do hereby declare "the following to. be ai full, clear, and exact" description` of thelinventionpsuch as will en- '.-'ableothers-.skilled in theart'to which itappertainst'o`make and use the. same.

' lThisinvention'relates/co1projectilesfor'at` claims.

j tion; Fig. .2, is". ani enlarged". 'detail sectional" or to the :rear ofthe.plate,.itisof'necessity forced' to` flow: to the fronti-'off the plate and 4nature which will? be more r eicient yin actionI and.` more accurate in `flight over longfranges 'A nations l of parts more fully hereinafter"I dis` ters, 'the plate-somewhat likea': Wedge; andfy CLELAND; DAVIS,` OF THE 'UNTED STATES NAV-Y.

PnoJEoTILE non. ATTACKING nAcE-HARDENED' ARMOR.

Specification of Letters Patent.

Patentedfuly 11, i911.

application-med Juneie, i910.-v serial ivo.. misas.v

Be it knovvnthz'itS I., GLtELAND DAvislieus a citzen of theV United!USt-altes,A at present attached: tothe U, S. S.- Missz'ssippahaveintac'ki'ng face hardened-` armor plates, and Ahas forl its. object to producefa-` device ofk this' than has beenjpossible heretofore; iTo't-hese; ends they invention consists in:- thes novelf details of. construction .f and combiclosed and' particularly' pointedf out in the' Referring to, thefaccompanyi'ng drawings forming-a part' of-this specification, in lwhich' likefnumeralsfrefer to/ likefpai'tsA in all the views :'tFigureV -1y isap'lan. vievv of a projectile made in accordance .With my inven-l vievv' off-aV slightlymodifiedxform= ofv my in- ,ventiong-y and, Fig. 3, is; a` view, partlyin section, of aprojectiler notv provided with a 41Y indicates-thebody portionfoffan standard roj ectile andl 2.; the :hardenedV head2 thereof,

at this. stage, since* the metal' is necessarily displaced, and cannotAV escapeeither` sidewise forms-the .Wellfknovvnfringe aroundfthe shotf hole; As the .pointedv projectile gets` farther"J intoxthe plate,however,1 .therear VWall of` thea non+f`acehardened plate is a pointed the opposite `is true` of ak face *hardenedv` plate. Forit is evdent,the lessv platef'begins-tof givervvay; and? thev displacedy metal. thereupon is forced first into the bulge formed' at the rear-,and later whenthe plate is perforated, itlikewise forms the familiar Arear fringe. around the Shothole. AVVitha face-hardened armor plate, however, the

kaction is 'quite different when the projectile isk not provided With a soft steel cap.- In suchlcase, upon impact the plateis first elas tically dishedvvithout penetration'.` When it islin this condition it is evident that the' strains' and stresses are-concentrated at or -near the point of maximum displacement and react tothi'ovvy the projectile back" or out of the elasticallv dishedf portion,-very much as ay bow' string underltensioni throvvs an arrow. Shouldv the head of the projectile be sufficiently' ,strongy andC have sufficient energy, its'pointpfwillbreak through this elastically' dished/j-portion; The hardened face, however, of the plate-Will' prevent anyvflovvfv of metal toward thev front, and the Whole of thedispla'fted metal, must, therefore, flow to'therear ofthe plate.y Upto this stage A i i infbothf-cases, there is, of course, a great deal of ene gy consumed inv displacing in appreciablel quantities of metal sidevvise, but

vmuch less/ energy is lost .inv this sidevvise' Y action -in lhomogeneous plates, the projectiles beingfthe/same, than in face=hardened plates, because `inthe formercase, the metal escapes to the front as above pointedV out, and,

therefore, the' lateralv compressive actions' arenot sosevere. `These actions, actually carrying metal to the rear and` tending strongly to displace 'j it lat'era'lly,.continue-inl face hardened:l plates until the loourrelet f enters the plane ofthefront face, Whenthe furtherpenetrative action becomes a pure vpunching or shearingactomf AL comparison of these twoeffects strongly indicates that While fthe best-form ofhead for penetrating .tapering one,l

the lateraly stress the greater" will be the energy left in the projectile'to be applied to shearing strains and to punching actions.

:In other Words, projectiles for attaching .'face-hardened-armor should bei provided with. heads best:y adaptedf` for a' punching action, andi this isv true Whetherthe projectile isor is not providedl with a` soft' steel cap4 7 The function ofv sucha` cap in at 110AA tacking'g'face-hardened armor is' toabsorb :theenergy of'impactvandvthereb'y relieve the i -1 point'y ofthe :proj ectile of considerable strainioo therefore, follows, when a soft steel cap is' employed that the point olf the projectile after/passing through the cap finds itself less strained and, therefore, stronger than when no cap is used, and the plate being' already elastically dished isof course, more easily penetrated. It follows, ifthe head 2 of the projectile is provided with the ogival contour above set forth, greatly improved destructive powers are imparted to the projectile, but, as is evident fromv the drawings, such contou-r is so blunt that it engenders an abnormal resistance to the air in long flights. As pointed out in my prior patent, Number '9l5,492, January 4, 1910,in order to def crease this air resistance to a minimum,'the contour of thehead of the projectile as a Whole should be struck with a'radius of about six orl seven calibers. Therefore, in order to provide a projectile capable of piercing face-hardened armor with ay maximum eiiciency and at the same time capableY of piercing the air with a minimum resistance, and, therefore, of having a flatter l'trajectory and a greater danger .zone and a greater accuracy-over long ights than heretofore, I provide the projectile with an outer contour cap or Wind shield Whichis struck with a radius of substantially seven calibers.. The contour cap 8 may be attached .to the v projectile by-anysuitable means, and in the drawings. I have shownits rear end n Fig.

3 as being swaged .or let into a groove 9, While in Fig. 2, I have shown a support 10 secured to the cap 7,v as by screw4 threads.

yIt is obvious that those skilled in the art.

may 'vary the arrangement of parts and details of construe-tion without departing from the spirit of my invention and, therefore,

I do not wish 'to be limited to such details, except as may be required by the claims.

What I claim is l. The combination ofan armor piercing projectile having ahead a portion of .the contour of which is struck with a radius of substantially one diameter-of the projectile, whileanother portion of saidl contour has a radius of less than one diameter of said projectile; a soft steel cap carried by said head; acontour cap having aradius`of curvature of substantially seven diameters of said projectile; and means for securing said contour cap to lsaid projectile, substantially as described.

Q. The combination of an armor piercing projectilehaving a. hardened head a portion of the contourof whichcomprises an o'gival struckwith a radius of substantially one diameter of the projectile over a greater portion. of its surface, and an ogival struck With a radius of less than one diameter of the-projectile over a less portion of its sur- :face; and a hollow contourcap having-a radius of curvature of. substantially sevendiameters of the projectile, substantially as described.

whereof, I affix my signa 

